Rotary electric switch



ROTARY ELECTRIC SWITCH Filed Dec. 28, 1945 INVEINTOR GILBERT s.ELLITHORPE ATTORNEYS BY 7 I I FIG. 4 a) Patented Jan. 25, 1949 UNITEDSTATES rArEnT OFFICE ROTARY ELECTRIC 'SWITCH Gilbert ;S.- Ellithorpc,Chicago, Ill.

Application December 28, 1945, Serial No. 631,655

Claims.

1 This inventionrelates to switches ofthe general type employed onvcontrol panelsofradio apparatusandthe like, and has particularreference to improvements in the form and-arrangecment of parts thereof.

Then-lain objects of this invention-are to pro- --vide an improvedconstruction'ior small rotary ing position detent and as the agency. forproducing yielding pressure between the contact arm and contactterminals.

A specific embodiment of this invention is illustrated in theaccompanying drawings in which:

Figure 1 is an exploded perspective .view of the parts of a rotaryswitch'designed according to -25 this invention for mounting it upon acontrol panel.

' Fig. '2 is an elevation of thedisc that carries'the contact terminals.

'3 is an axial section of the switch assemblage.

Fig. 4 is a section taken on the line 4-.4 of Fi In the form shown theoperating shaft l is provided with a knurled end portion 2 of reduceddiameter that is splitlongitudinally at 3 for frictional connection withthe operating knob 4.

The shaft I is rotatable in a bus-hing 5 which is appropriatelyshouldered to engage a panel aperture and threaded to receive a nut-6whereby the bushing is clamped to the panel I. The bushing carries a.housing shell comprising a base disc 8, to which the bushing iscentrally attached, and a cylindrical wall 9 which is closed at itsouter end by the contact disc Ill which is held in place by lugs I! forthe receipt of which the disc Ill has peripheral notches l2, the lugs llbeing clenched, as shown in Fig. 2 for holding the disc I!) in place.

The disc I0 has secured thereto by rivets l3 a central contact terminalI l and a plurality of conductor terminals concentrically arranged withr'espect to the axis of the switch so that their respective rivets l6will be radially spaced from the central rivet I3. The rivets l3 and I6have button heads at their inner ends which serve as switching contactsaswill be understood. 9

Fixed on theinner end of the operating shaft I is a contact pressurespring qr operating spring ll comprising a'hub portion I8, having a pairof diametrically opposed arms l9 extending therefrom in 'theplane ofthehub portion and'terminating in outstanding lugs 20 which aregenerally parallel with the axis of shaft I. Other radial arm-portionsor bowed members 2| and 22 of the spring are separated from the hubportion l8 by crescent-shaped slots 23 to allow them to flex readily.

Thearm 2| is depressed orinclined frqm the plane of the hub 18 and isshapedto form at its mid point a spherical 'detent projection 24 whichcooperates with a series of detent sockets 2 5 in the base :8 of thehousing to provide position stops corresponding to successive switch armpositions. The arm'2l also has appropriate shoulders ,25ior coactionwith one or two limit stop lugs 21 struck out from the housing base 8 inappropriate positions for limiting the-movement of theswitch arm inopposite directions.

The bowed arm portion 22 is bent out from-the plane of the hub .lflintheopposite direction from the bending of the armpZl so as to-forma-pressure ridge 28 which bears against a floating-insulating disc orswitch operating member 29 that is-peripherally recessed at .30-toloosely receive the driving lugs 2llwhereby the disc or operating member29 is rotated by the springbutmay move and tilt axially to some extent.

The disc has a pair of radially spaced apertures 3| and 32 which receivespaced lugs 33 and respectively on the switch arm 35which isshapedappropriately 'tobridge the 1 gap between the central terminal studs I3and the studs -16, as will be understood from Fig-"3. The lugs '33 andloosely :engage the apertures 3| and 32 so that the -arm 35 isfreetotiltand make proper contact with-the heads of-the studs 13 and i6asit rides over these heads. The arm 35 has a spherical projection 36which serves as a fulcrum bearing on the disc 29 at a point about midwaybetween the center contact l3 and the arc in which the contacts l6 lie.It will be noted that the pressure ridge 28 of the spring I? bearsagainst the disc 29 so as to cause said disc to bear against the fulcrum36 and force the switch arm 35 into firm engagement with the contactstuds l3 and Hi.

In theform shown the terminals l4 and I5 are L-shaped clips comprising abase 8! perforated to receive the attaching rivet and having a lu 38seatedin a perforation 39 in the disc ID to prevent 'iotation of theclips about their rivets.

In operation, the switch arm 35 always bears on the central contact studl3 and rides over the contactstuds 16 as the shaft is rotated. Thespherical .-;f ulcrum 36 and loosely held studs 33 and34' low the switcharm to tilt freely upon the operating disc 29. Rotation of the shaft 1rotates the disc 29 through the lugs 20 on the spring I l; and the disc29, through lugs 33 and 34, rotates the switch arm 35. The positiondetents 24 on the spring I! coact with detents 25 on the housing 8 toaline the switch arm 35 with the respective contacts, while the arm 22of the spring transmits the necessary contact pressure through dies 29and fulcrum 36. The novel construction of the spring ll,- providesadequate support and driving power for the disc '29 and switch arm 35and the bowed formation of the arms I'! and 22 provides a durablestructure even when the material of the spring is quite thin forsensitivity of fiexure. The bowed arm 2! braces the detent lug 24 insuch manner as to provide :both tension and thrust resistance tooverthrow of the knob 4 when the lug 24 abuts the limit stops 21.

Although but one specific embodiment of this invention is herein shownand described, it will be understood that numerous details of thestructure shown may be altered or omitted without departing from thespirit of the invention as defined by the following claims.

Iclaim:

1. In a rotary switch, a housing, a shaft extending into said housing, afloating switch mechanism in said housing rotatable on the axis of saidshaft, and an operating spring comprising a hub fixed on said shaft,diametrically opposed arms extending outward from said hub and op-,eratively connected adjacent their ends to said switch mechanism, and abowed member spaced from said hub and having its ends attached to saiddiametrically opposed arms respectively and bent to normally hold saidbowed member in a plane intersecting the plane of said opposed arir s, adetent on said bowed arm, and switch positioning detents on said housingcoacting with the detent on said bowed arm.

2. A rotary switch, comprising a shaft, a bearing forf said shaft, acup-shaped housing fixed on said bearing, a dielectric disc mounted onsaid housing,- a pair of radially spaced contact terminal's mounted onsaid disc, a contact arm rotatable into and out of contact with saidterminalsy'amovable insulating'disc supporting said contact arm, aspring plate fixed on said shaft and comprising arms tiltably supportingsaid movable dies and other arms respectively bearing inoppositedirections on said insulating disc and cup shapecl housing.

3. A rotary electric switch, comprising a pair of spaced parallelplates, a shaft journalled at right-angles to one of said plates, one ofsaid plates having thereon a plurality of circuit terminals angularlyspaced about the axis of said shaft, a contact arm coacting with saidterminals, the other plate having position detents located to correspondwith different contact arm positions respectively, and a drivingconnection between said contact arm and shaft, comprising an insulatingdisc carrying said contact arm and having angularly spaced lug recessestherethrough, and a spring between said insulating disc and shaft andcomprising a hub portion fast on said shaft, said spring having lugsaxially slidable in said lug recesses said spring having a. pair ofradial arms, one normally urged to bear toward and cooperate with saidposition detents and the other normall urged to bear on said insulatingdisc.

4, In a rotary switch, a housing, a shaft ex tending into said housing,switch mechanism in said housing, a floating operating member for saidswitch mechanism, a spring connecting said shaft and said operatingmember,saidspringcomprising a hub fixed on said shaft and havingdiametrically opposed arms extending radially therefrom and operativelyconnected adjacent their ends to said operating member, a bowed memberspaced from said hub and having its ends attached to said diametricallyopposed arms respectively and bent to normally hold the bowed member ina plane inclined to the plane of said hub, a detent on said bowedmember, and switch positioning detents on said housing coacting with thedetent on said bowed member.

5. In a. rotary switch, a housing, a shaft extending into said housing,switch mechanism in said housing, a floating operating member for saidswitch mechanism spaced from the inner end of said shaft, a springconnecting said shaft and said operating member, said spring comprisinga hub fixed on said shaft and having diametrically opposed armsextending radially therefrom and operatively connected adjacent theirends to said operating member, a pair of bowed members spaced fromopposite sides of said hub and each having its ends attached to saiddiametrically opposed arms respectively and bent to normally hold therespective bowed member in a plane inclined to the plane of said hub,one of said bowed members being inclined toward and bearing against saidoperating member and the other bowed member being inclined oppositely, adetent on said other bowed member, and switch positioning detents onsaid housing coacting with the detent on said bowed member.

GILBERT S. ELLITHORPE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

